Electric signal-responsive device



3 Sheets-Sheet l Mug/Mar by fi E. A. H. BOWSHER ELECTRICALSIGNAL-RESPONSIVE DEVICE Filed March 15, 1940 Sept. 8, 1942.

3 Sheets-Shet 2 E. A. H. BOWSHER ELECTRICAL SIGNAL-RESPONSIVE DEVICEFiled March 15, 1940 Sept. 8, 1942.

p -8, 1942- E. A. H. BiCSWSHER I 22!?5 025 ELECTRICAL SIGNAL-RESPONSIVEDEVICE Filed Marh 15, 1 940 3 Sheets-Sheet 3 Inns/7hr Patented Sept. 8,1942 Applicat-icn March 15, 1940, Serial No. 324,117

I Grea B t March 1.939

1 Claim. 191. 177-35 This invention relates to mechanism responsive toelectrical-impulses.

In the prior British Patent No. 495,057, there is described a system forthe remote control of various independent pieces of electricalapparatus, a system which could conveniently utilise for thetransmission of the controlling impulses the power line actually feedingthe apparatus in question. As there described, an initial impulse fromthe control station starts up a synchronous motor at each of the severalreceiving stations, to drive a switch through a certain cycle ormovement and then come to a stop; a signal impulse, sent out at adetermined point in the cycle, afiected any individual switch or left itunaffected according to the setting of the switch. 4'

clearly understood that the invention is not restricted to use in thesystem described in the prior British Patent No. 495,057 referred toabove, since it may be applied to other purposes without the exercise ofinventive ingenuity.

In accordance with this invention a mechanism selectively responsive toelectrical impulses is characterised by two elements which are adaptedto move relatively one at least being deflected upon receipt of animpulse, and which are set with respect to one another so that one willact upon the other if the deflection due to a received impulse occurswhilst the two elements occupy a lcertain relative position. Thus themechanism is selective in the sense that an impulse received during therelative movement of 'theelementsis effective or non-efiective to causetheir interaction according as the mechanism has been previously set sothat the two elements occupy the certain relative position referred toat the moment when the impulse-causes deflection.

The invention will be clearly understood from the following descriptionof two embodiments shown in the accompanying drawings, inwhich:

Fig. 1 is a plan view of a mechanical impulse- ;responsive device inaccordance with the inven- .tion;

21s a front view; Figs. 3 and 5 are views of details; Fig. 51 isacircuit diagram;

Fig. 6 shows details of the switch controller mechanism.

Describing a preferred embodiment, and referring to the circuit shown inFig. 4 in order to gain a general concept of the functioning of thedevice, one sees that the power line LN,is connected through to aparticular apparatus constituting a load LD, when the main contacts MCare closed. A magnet M is arranged in series with one winding of atransformer TR, and as both windings of the transformer bridge the powerline LN the magnet M is rendered insensitive to alternating currents butremains responsive to direct currents put out over the power line.Energisation of the magnet M by a direct current impulse closes thenormally open contacts CI to operate intermediate relay 1 R from atapping on transformer TR; and relay JR closes switch-CNS for the motorso that the latter will start on its cycle, and once started the ofinorn al switch QNS is closed to maintain energisation of the motordespite release of the switch Cl, until a spindle Sp, driving amechanical switchlcontroller SC forthe main switch MC, has executed adefinite cycleof movement, say one complete revolution during a time ofone minute. If during this cycle, a second impulse of direct current isreceived by the magnet M, the switch controller SC will be influenced ornot, according to its previous setting and the timing of the impulse.

Referring now to the more detailed Figs. 1 and 2, there .isshown .a baseplate BP, with the transformer T1 at one side, the motor and its step dwn eearingbelow, an th Sp le ppassin up through the base plate toabearing in the top plate TP. The inasnet M is disposed beneath the baseplate, .and the intermediate relay 1 R above it.

Above ,-base .platelBP and rotatably mounted on spindle Sp is a springdrum assembly consisting of .the .oval cam plate P I, the-circular:plate P2 and the latch bar LB. LB isfixed to P2 and P2 is separatedfrom PJ- by a series of pins R. A main spring MS has its inner endfastened to the p d e, gbut its .outer end is free to slip past th pinsR when the spring is over wound. When the spring is unwound, it isconfined by pins R. Thus, every revolution of the spindle winds orovertwinds the spring} because the spring drum assembly is preventedfrom rotating loy latch bar LB engaging with'levers L3 or L l which are.held ,a, gainst their stops {0 by springs S3 and S4 respectively.

Referring to Fig- ,6, i Will be seen that the .rpositionpf the springdrum assembly just dc.

scribed controls the position of a lever BC, pivoted at I having aprojecting arm H which engages with the oval cam plate PI. On lever BCis mounted one of the main contacts MC. Spring I8 attached to BC tendsto rotate lever BC to close contacts MC.

When the spring drum assembly is in the position shown by the full linesof Fig. 6, contacts MC are closed and latch bar L3 is in engagement withcrank CL of lever L4, but if this crank is rotated outwards, it allowsthe latch bar to pass, the spring drum assembly rotating through 90degrees under tension of main spring MS. The latch bar then engages withcrank CL of lever L3, the oval cam plate PI deflects arm I! of bellcrank BC against the tension of spring I8 and contacts MC open. Thisarrangement is similar to an escapement. Subsequent deflection ocf leverL3 outward on its pivot, in a subsequent selecting operation, causes theassembly to rotate through a further 90 degrees and the contacts closeagain.

The levers L3 and L4 are in the form of wires pivoted at the top andbottom in the plates TP and BP. A crank CL is formed in the intermediatepart of the levers, and a kink X is formed in the upper arm of the crankas shown in Figs. 1 and 5. Springs S3 and S4 urge the levers in aclockwise direction and hold them normally against stops I0, Fig. 1, sothat cranks CL normally lie in the path of latch bar LB.

Above the spring drum assembly on the spindle Sp is an oil-normal camONC, which is notched at one .point in its periphery so as to allow oneof the contacts ONSI of the motor switch to drop away from the other.The other contact ONS2 is normally held out of engagement with the firstby a latch ALI carried on the armature of the relay IR; so that uponoperation of relay IR contact ONS2 springs into engagement with ONSI tostart the motor, and thereafter the pair of them ride up on theperiphery of the cam ON C.

The cam ONC carries an abutment ONA which is adapted to engage with asecond latch AL2 on the armature of relay IR so as to move the armaturein its direction of operation.

Finally, the spindle carries a lever displacing assembly LD. Thisincludes an arm which is fixed on the spindle and which carries a U-shaped finger H, the arms of which are pivoted on a pivot II on oppositesurfaces of arm DI, and which is urged by spring I2 in anti-clockwisedirection so as normally to lie in the position shown against the edgeof the arm. Beneath arm DI is a releasing disc D2, which is rotatable onthe spindle but connected with it through a spring DS wound up if thedisc is held while the spindle rotates. This releasing disc D2 carriesan abutment DA which engages with the second latch AL2 on the armatureof the relay IR.

Immediately above the release disc D2 is a striker disc D3 which isfixed with respect to the disc D2 and is therefore connected with thespindle for driving purposes, only through the spring DS. The strikerdisc D3 has a projection I3 adapted to engage with the tail I4 of thefinger H and displace it clockwise.

The following is the operation of this device: A first or startingimpulse of direct current energises magnet M and hence causes relay IRto be fed with alternating current from the mains LN. Attraction of thearmature of relay IR will cause the latch ALI to release the contactspring ONSZ, thus closing the switch CNS and starting up the motor. Oncethe spring ONSZ has been released by the latch ALI, the motor continuesto run despite subsequent release of relay IR, the latch ALI simplystriking against the extremity of the spring ONS2. Moreover the spindleSp in its rotation carries round the cam ONC so that the springs ONS,although remaining in contact, are moved out by the edge of the cam, andremain so until at the end of one complete revolution the inner springONSI drops into the cam notch, leaving spring ONS2 again caught by latchALI.

At an early stage in the movement, but after the relay IR has beenallowed to release, the abutment DA on the release disc D2 reaches thelatch AL2 on the armature of relay IR. Release disc D2 and striker discD3 stop, and the continued movement of the spindle Sp winds up thespring DS. The arm DI on the other hand, carrying finger H, continues inrotation, being fixed on the spindle.

If now a second or signalling impulse is received, the relay IR againoperates, with the consequence that latch AL2 frees abutment DA, and thediscs D2 and D3 fly round under the force of spring DS to catch up withthe arm DI. The tail I4 of the finger H is then struck by the projectionI3 on disc D3, and the finger is turned round clockwise until, if itspath is clear, it will have its extremity lying radially outward beyondthe cranked part CL of the lever L3 or L4. In this case, on engagementof finger H with lever L3 or L4, the finger will not move the lever butwill rotate on its pivot I I in a clockwise direction against thetension of spring I2 with the continued rotation of arm DI until the endof the finger disengages from the lever when spring I2 partly restoresthe finger toward its normal position depending on the position ofprojection I3, as shown in Fig. 3. It will be understood that thestriker projection I3 after having once tripped finger H is ineffectiveto cause another operation thereof until the spring DS is tensionedprior to another selecting cycle.

If the signal impulse should come in during that portion of the cyclewhen the finger H is adjacent one of the levers L, the finger will beunable to turn out beyond the cranked part CL, but will strike againstthe horizontal part of the lever and there stay. Continued movement ofthe spindle will carry the end of the finger into the kink X in thelever L and will then force thelever to move outwardly until the latchbar is released. The latch bar assembly being under tension of spring MSturns until either arm of latch bar LB comes into engagement with alever L3 or L4 changing the position of the assembly and oval cam PIthereof degrees thus reversing the position of contacts MC.

On the other hand, should no signal impulse occur during the cycle thespring DS might be over-wound, and in order to prevent this theabutunent ONA is provided, which will displace the ar- :mature latch AL2and thus release the discs D2 and D3 shortly before the end of thecycle.

Setting of the device to respond to a signal impulse at a certain pointin the cycle, is accomplished by angular adjustment of the arm DI withrespect to the spindle, or more correctly with respect to the cam ONC,and by a corresponding angular adjustment between th striker disc D3 andthe release disc D2.

It will be seen that with this embodiment of the invention, theoperation by which the finger H is displaced i. e. the release of latchALZ, is independent of theduration of the signal impulse.

What is claimed is: T

In a device of 'the character described, the

combination of an oval cam, a yielding drive for said cam, a contact armengaged by said cam to be moved to open or closed position thereby, anescapement comprising a stop arm secured to said cam and lever meanscooperating therewith, a 5

motor :for turning said yielding drive, a power line, a magnet connectedto said line arranged to respond to impulses transmitted thereover,means controlled by said magnet in response to an initial impulse tostart said motor, means to cause said motor once started to rotateindependently of said magnet, means responsive to an operation of saidmagnet by an impulse transmitted in a predetermined interval after saidinitial impulse to operate said escapement lever means and therebypermit said cam to change the position of said [contact arm.

EDWARD ALBERT HENRY BOWSHER.

